Connector



A ril 23, 1968 w. GOMULKA 3,380,017

CONNECTOR Filed July 9, 1965 FIGZ 47 I 44 45 F|G.5

INVENTOR WILLIAM GOMULKA ATTORNEYS United States Patent 3,380,017 CONNECTOR William Gomulka, 149 Ormond St., Mattapan, Mass. 02126 Filed July 9, 1965, Ser. No. 470,761 4 Claims. (Cl. 339-407) ABSTRACT OF THE DISCLOSURE A coupling device is provided wherein a constant diameter coil spring is mounted within a two-part insulating housing and restrained from movement along its axis. The spring is allowed to expand radially but not move in any axial direction whereby positive locking of a contact can be made. In an alternate embodiment, a slideable sleeve member having two diameters with a surrounding coil spring is employed to provide for locking an electrical connection of a contact.

It is an important object of the present invention to provide a coupling device for contacting and positively holding one or more elongated members at a joint which can have a controlled resistance to separation.

Another object of this invention is to provide a coupling device in accordance with the preceding object which forms a good electrical connection with a conductor held in the device with positive pressure exerted to maintain the conductor in the device in firm electrical and mechanical contact.

A further object of the present invention is to provide a coupling device in accordance with the preceding objects which permits rapid and efiicient connection with a member to be joined therewith.

Still another object of this invention is to provide a coupling device in accordance with the preceding objects which is relatively easy and inexpensive to manufacture.

Yet another object of this invention is to provide a coupling device in accordance with the preceding objects which may be readily miniaturized and which is capable of withstanding severe mechanical strains, stresses and vibrations without harmful effects.

According to the invention the coupling device is a connector having a housing defining chamber. A coiled spring is mounted in the chamber with the chamber having a larger diameter than the outer diameter of the coiled spring. Means are provided for restraining the spring from elongation along its axis to prevent it from increasing in length within the chamber. Directional means are preferably provided for directing an elongated member to be connected with the connector, towards and into an opened end of the spring axially thereof, to cause the spring to be resiliently expanded in diameter preferably without increasing the axial length of the spring.

Preferably the connector is used for electrically contacting an electrical conductor such as wire or cable with a contact terminal or with another wire or cable. The housing is preferably insulated and encloses the electrical joint formed within the connector. The spring action of the coil spring, when it is expanded in diameter by an electrical conductor forced within the coils and having a larger diameter than the inside diameter of the coils, acts to positively hold the conductor and provides for good electrical contact between the coils of the spring and the electrical conductor.

In an alternate embodiment of the invention, the spring action is indirectly employed to hold an electrical conductor.

3,380,017 Patented Apr. 23, 1968 These and other objects, advantages and features of the present invention will be more clearly understood from the following specification when read in connection with the accompanying drawings in which:

FIG. 1 is a perspective view, partly in cross section of a preferred embodiment of this invention;

FIG. 2 is a cross sectional view through the center of the preferred embodiment of FIG. 1 showing an electrical conductor positioned therein;

FIG. 3 is a top view of an alternate embodiment thereof with the cover removed;

FIG. 4 is a view of the cover for the embodiment of FIG. 3; and,

FIG. 5 is a cross sectional view through the center of another embodiment of the present invention.

Turning now to the drawings and with particular reference to FIGS. 1 and 2 a connector 10 is shown comprising a two part housing 11 of an insulating material such as Bakelite, polyethylene or other plastic. The housing 11 is comprised of a shell 12 preferably molded with a circular bore 13 opening on one face of the shell 12 and ending at a rear wall 14. A cap 15 in the preferred embodiment comprises a flat rectangular plate which is glued or otherwise secured to close the opening formed by bore 13 thus forming a closed chamber 16 within the housing 11. A centrally located hole 17 extends through the cap 15, preferably having a chamfered outer end 18, and acts as a directional means for directing conductors or other elongated members to be connected to a coil spring 20 positioned in the chamber.

The coiled spring 20 is preferably made of a conventional resilient electrically conductive metallic material and has one open end adjacent the inner end of bore 17 and extends axially thereof in the chamber 16. The last coil of the spring 20 at the second end abuts the rear wall 14 so that no movement of the spring is possible to cause elongation of the spring along its axis. The turns of the helically coiled springs preferably are adjacent each other and touch each other to form a substantially continuous cylindrical wall. In some cases the turns of the coil spring can be slightly spaced from each other or the distance between the front and back walls of chamber 16 can be greater than the axial length of the spring 20 so long as the spring is not deformed in length, by insertion or removal of an elongated member, beyond its elastic limit. An integral wire end 21 of the spring extends outwardly through a suitable bore 22 provided in the housing 11. Wire end 21 preferably snugly fits within the bore 22 and may have an insulated sleeve thereover. This end may be connected to a conventional circuit arrangement as desired.

Preferably bore 23 is axially aligned with bore 17 and of equal diameter extending in rear wall 14 short of the outer surface of the casing. It is important that the outer diameter of the spring 20 be less than :the inner diameter of chamber 16 so that when an elongated member such as male connector 24 is inserted in bore 17 through the open end of the hclically extending coiled spring 20, the spring can expand in its diameter without expanding longitudinally and the spring will thus resiliently grip the male connector 24 as best shown in FIG. 2. The spring can be caused to expand radially into contact with the wall of bore 13 when a male prong or conductor is inserted. The inner diameter of the coiled spring is always less than the diameter of bore 17 while the outer diameter of :the coils of spring 20 is always greater than the diameter of bore 17 to prevent the spring from falling out of the housing. Spring can be attached to the housing as by a tight fit of wire end 21 in bore 22 or the spring can lie loosely in the housing. Bore 23 provides for extension of the male prong beyond the rear end of the helically coiled spring.

In operation of the device of this invention, when a male conductor 24 or other elongated member to be joined is inserted through bore 17, the coiled spring 2% is expanded outwardly into the space provided by the chamber 16 and the coils of the spring frictionally grip the male prong 24 and resiliently hold it in the connector.

While a specific housing structure has been shown and described, it should be understood that this embodiment includes various modifications among which are one piece housing units or various shaped housings so long as a mounting is provided for the spring member preventing it from deformation beyond its elastic limit during insertion or withdrawal of the elongated member to be connected. In some cases bore 23 can extend completely through the rear housing wall 14 permitting connection of a second prong through the rear wall of the housing to interconnect two electrical connectors or other elongated members. In such case, lead end 21 can be omitted and the casing closed except for the bores 23 and 17. Lead end 21 can be directed to pass through other portions of the housing such as out of the housiru through the bore 17 by providing a suitable channel coextensive with bore 17 or any other lead opening of the housing.

In an alternate embodiment of this invention a multiple spring housing as shown in FIGS. 3 and 4 is provided. Housing has a base member 31 in a dish form having a plurality of and preferably six elongated channels 32 extending radially thereof. Springs such as 20 are positioned Within the channels 32 and stop means provided by integral molded projections 32a prevent axial elongation of the springs.

A cover 33 is provided which is clamped to base 31 by use of a nut (not shown) threaded over screw 35 which passes through bore 34 to lock the cover in place. The circular channels 32 formed in part by the cover 33 have a larger diameter than the outer diameter of springs 20. Openings or bores 32b have larger diameters than the inner diameters of springs 20 while the outer diameter of each spring is larger than the diameter of each opening 32b. In some cases a central projection fits within circular recess 36 in the base 31 and acts as a stop means to clamp links 20a and stop axial elongation of the springs when a male connector is pushed within the springs through openings such as 38 and 39.

In the specific example shown, pairs of the springs 20 are formed integrally as by integral wire links 20a. This embodiment functions in a similar manner to the embodiment of FIGS. 1 and 2 to grip a male member inserted through bores 32. Two wires may be interconnected by inserting one of the ends through one opening such as 38 and a second of the wires through a second opening such as 39.

Many variations of this embodiment 30 are possible. For example all of the coil spring members 20 may be electrically interconnected. Alternately one or more of the coil spring members may be electrically isolated from the other coil spring members with an end of the coil wire passing out of the housing as in the embodiment of FIG. 1.

In still another embodiment of this invention, as best illustrated in FIG. 5 the coil spring action is used to indirectly transmit pressure to a male member. In the embodiment of FIG. 5 an insulating housing 40 is formed having a first bore 41 in a shell 40a for entrance of a male member to a female member positioned therein and a second enlarged bore 42 with a closing cover plate 43. A resilient, conductive metal tube acts as a female receptacle comprising a first end section 44 of larger diameter than a second end section 45 with a flared sliding surface 44a therebetween. A split lock washer locks the tube in the housing. End 45 of the female receptacle comprises a tube passing through a suitable bore provided in the cap 43 in sliding engagement therewith. The end 44 is longitudinally split into two semi-circular portions having a notch 46 formed therebetween to allow for resilient expansion of the female receptacle. A coil spring such as 20 is mounted in the bore 42 with spacing provided between the outside diameter of the coil spring and the bore surface. Coil spring 20 surrounds portion 45 and is preferably not mounted or fixed to the housing.

In operation of this embodiment of the inention, when a male prong is slid axially within the end 44 of the female member it can expand slightly and is pushed to the right as shown in FIG. 5. This axial movement to the right as shown in FIG. 5 causes the coil spring 20 to be expanded in diameter as the portion 44 moves axially within the coil spring. Thus the resilient closing action of the spring forces the halves of portion 44 into tight engagement with a male prong member such as 24 or any other elongated member forced within the female receptacle. The male or other elongated member always has a larger diameter in combination with the thickness of the female receptacle 44 than the inner diameter of the coil spring at rest and the coil spring is fixed against elongation along its axis or prevented from deforming beyond its elastic limit during insertion or withdrawal of the elongated member. The coil spring can be fixed to the cover plate 43 at one end and to the shell 40a at its other end. Alternately either end can be mounted in fixed position so long as the spring 20 is not axially extended beyond its elastic limit by insertion or withdrawal of a male prong. Electrical connection may be made by conventional means to the end 47 passing out of the insulated housing provided in this embodiment. Alternately a wire end such as 21 of FIG. 2 can be used to contact a terminal of a circuit.

While specific embodiments of this invention have been shown and described, it will be understood by those skilled in the art that many variations thereof are possible. It is only necessary that a coil spring clamping and contacting action be employed to make good mechanical and electrical contact with an elongated member by expanding the spring radially while restricting elongation of the spring. This feature provides controlled forces tending to clamp an elongated members inserted therein to form a good electrical and mechanical joint. The withdrawal and insertation force can be varied depending on a particular application as by proper selection of the spring and housing used. While round wire is preferred for use in the helical springs used the springs can be formed of square, rectangular or other cross sectioned members. The plastic or insulating housings may vary considerably in configuration. In some cases metallic housings can be employed.

lural spring devices can be formed. Two or more male prongs can be forced Within a single spring 20 to form a connection. Therefore this invention is to be limited only by the spirit and scope of the appended claims.

What is claimed is:

1. An electrical connector comprising a two-part insulated housing defining a chamber,

at least two constant diameter helically coiled elongated springs With adjacent turns of each spring coil lying in contact with each other in tight helical form, said springs being mounted in said chamber with said chamber defining an elongated axially extending space surrounding coils of each spring, means on said housing for restraining each of said springs from substantial elongation along their axes when a force is applied at first ends thereof and from movement in either direction along their axes,

said two springs being electrically connected with each other by a common wire Within said housing,

and at least one opening defined by said housing adjacent an opened end of each spring enabling access to said opened ends of said springs whereby elongated conductors can be forced into said coiled springs axially thereof Without substantially elongating said springs but radially expanding said springs to cause tight contacting of said conductors by said springs.

2. An electrical connector in accordance with claim 1 wherein said chamber comprises a plurality of radially extending channels for mounting said springs.

3. A connector comprising a housing,

an elongated metallic tube positioned in said housing and having a first end portion of larger diameter than a second end portion,

a helically coiled spring means surrounding said smaller diameter portion and coaxial therewith,

said first tube end portion having resiliently yieldable means comprising slots for gripping an elongated member placed therebetween,

and means for permitting sliding of said tube with respect to said spring means when a conductor is placed within said first end portion to cause said spring means to surround said first tube end portion and bias said yieldable means towards said conductor.

4. A connector in accordance with claim 3 wherein said housing is made of an insulating material and said means for permitting sliding of said tube comprises a circular opening defined by said housing.

References Cited UNITED STATES PATENTS 1/1928 Fortin 339-256 10/1929 Gilson 339193 4/1930 Rothen 339-191 10/1932 Crawford 339-193 3/1934 Douglas 3392l0 X 9/1947 Hubbell et a1. 339-256 X 8/1949 Adams 339-258 X 4/1958 Jacobs 339-198 10/ 1962 Schneider 339256 2/ 1964 Laszczewski 339-273 11/1964 Takano 339--256 1/1967 Benoit et a1. 339-259 X FOREIGN PATENTS 10/ 1951 Germany. 10/ 1952 Germany. 11/1953 Germany.

8/1926 Great Britain. 11/ 1931 Great Britain. 7/1934 Great Britain. 3/ 1932 Switzerland.

MARVIN A. CHAMPION, Primary Examiner.

PERRY TEITELBAUM, Assistant Examiner. 

